[PATCH v3 2/3] of: kexec: Refactor IMA buffer related functions to make them reusable

[Stefan Berger]

Refactor IMA buffer related functions to make them reusable for carrying
TPM logs across kexec.

Signed-off-by: Stefan Berger <stef...@linux.ibm.com>
Cc: Rob Herring <robh...@kernel.org>
Cc: Frank Rowand <frowand.l...@gmail.com>
Cc: Mimi Zohar <zo...@linux.ibm.com>
---
 drivers/of/kexec.c | 99 +++++++++++++++++++++++++++++-----------------
 1 file changed, 62 insertions(+), 37 deletions(-)

diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
index b9bd1cff1793..601ea9727b0e 100644
--- a/drivers/of/kexec.c
+++ b/drivers/of/kexec.c
@@ -115,6 +115,18 @@ static int do_get_kexec_buffer(const void *prop, int len, 
unsigned long *addr,
        return 0;
 }
 
+static int get_kexec_buffer(const char *name, unsigned long *addr, size_t 
*size)
+{
+       const void *prop;
+       int len;
+
+       prop = of_get_property(of_chosen, name, &len);
+       if (!prop)
+               return -ENOENT;
+
+       return do_get_kexec_buffer(prop, len, addr, size);
+}
+
 /**
  * ima_get_kexec_buffer - get IMA buffer from the previous kernel
  * @addr:      On successful return, set to point to the buffer contents.
@@ -124,19 +136,14 @@ static int do_get_kexec_buffer(const void *prop, int len, 
unsigned long *addr,
  */
 int ima_get_kexec_buffer(void **addr, size_t *size)
 {
-       int ret, len;
+       int ret;
        unsigned long tmp_addr;
        size_t tmp_size;
-       const void *prop;
 
        if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
                return -ENOTSUPP;
 
-       prop = of_get_property(of_chosen, "linux,ima-kexec-buffer", &len);
-       if (!prop)
-               return -ENOENT;
-
-       ret = do_get_kexec_buffer(prop, len, &tmp_addr, &tmp_size);
+       ret = get_kexec_buffer("linux,ima-kexec-buffer", &tmp_addr, &tmp_size);
        if (ret)
                return ret;
 
@@ -174,6 +181,28 @@ int ima_free_kexec_buffer(void)
        return memblock_phys_free(addr, size);
 }
 
+static int remove_buffer(void *fdt, int chosen_node, const char *name)
+{
+       int ret, len;
+       unsigned long addr;
+       size_t size;
+       const void *prop;
+
+       prop = fdt_getprop(fdt, chosen_node, name, &len);
+       if (!prop)
+               return -ENOENT;
+
+       ret = do_get_kexec_buffer(prop, len, &addr, &size);
+       fdt_delprop(fdt, chosen_node, name);
+       if (ret)
+               return ret;
+
+       ret = fdt_find_and_del_mem_rsv(fdt, addr, size);
+       if (!ret)
+               pr_debug("Remove old %s buffer reserveration", name);
+       return ret;
+}
+
 /**
  * remove_ima_buffer - remove the IMA buffer property and reservation from @fdt
  *
@@ -185,29 +214,34 @@ int ima_free_kexec_buffer(void)
  */
 static void remove_ima_buffer(void *fdt, int chosen_node)
 {
-       int ret, len;
-       unsigned long addr;
-       size_t size;
-       const void *prop;
-
        if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
                return;
 
-       prop = fdt_getprop(fdt, chosen_node, "linux,ima-kexec-buffer", &len);
-       if (!prop)
-               return;
+       remove_buffer(fdt, chosen_node, "linux,ima-kexec-buffer");
+}
 
-       ret = do_get_kexec_buffer(prop, len, &addr, &size);
-       fdt_delprop(fdt, chosen_node, "linux,ima-kexec-buffer");
+#ifdef CONFIG_IMA_KEXEC
+static int setup_buffer(void *fdt, int chosen_node, const char *name,
+                       uint64_t addr, uint64_t size)
+{
+       int ret;
+
+       if (!size)
+               return 0;
+
+       ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
+                                      name, addr, size);
+       if (ret < 0)
+               return -EINVAL;
+
+       ret = fdt_add_mem_rsv(fdt, addr, size);
        if (ret)
-               return;
+               return -EINVAL;
+
+       return 0;
 
-       ret = fdt_find_and_del_mem_rsv(fdt, addr, size);
-       if (!ret)
-               pr_debug("Removed old IMA buffer reservation.\n");
 }
 
-#ifdef CONFIG_IMA_KEXEC
 /**
  * setup_ima_buffer - add IMA buffer information to the fdt
  * @image:             kexec image being loaded.
@@ -221,23 +255,14 @@ static int setup_ima_buffer(const struct kimage *image, 
void *fdt,
 {
        int ret;
 
-       if (!image->ima_buffer_size)
-               return 0;
-
-       ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
-                                      "linux,ima-kexec-buffer",
-                                      image->ima_buffer_addr,
-                                      image->ima_buffer_size);
-       if (ret < 0)
-               return -EINVAL;
-
-       ret = fdt_add_mem_rsv(fdt, image->ima_buffer_addr,
-                             image->ima_buffer_size);
+       ret = setup_buffer(fdt, chosen_node, "linux,ima-kexec-buffer",
+                          image->ima_buffer_addr, image->ima_buffer_size);
        if (ret)
-               return -EINVAL;
+               return ret;
 
-       pr_debug("IMA buffer at 0x%llx, size = 0x%zx\n",
-                image->ima_buffer_addr, image->ima_buffer_size);
+       if (image->ima_buffer_addr)
+               pr_debug("IMA buffer at 0x%llx, size = 0x%zx\n",
+                        image->ima_buffer_addr, image->ima_buffer_size);
 
        return 0;
 }
-- 
2.35.1